I find that often, especially for new grads, it's not a "safety" issue so much as a confidence issue. You just don't THINK you can handle what you really CAN handle.
At the same time, new grads do need a lot of hand-holding that a lot of departments can't afford, because they need bodies out on the floor NOW.
As a result, these "sink or swim" situations are exceedingly common.
Personally, I do well with sink or swim. But I recognize that one size does not fit all.
My personal opinion, based on what you have posted, is that you should try to find a more supportive environment to first learn how to be a nurse- then, once you have your feet on the ground, transfer to something more specialized. I hate to tell new grads to cut their nursing teeth in Med/Surg, because IMO, Med/Surg *IS* a specialty- and it's not fair to that specialty to use them as a stepping stone or training ground for people that don't really want to be there.
And yet, at the same time, Med/Surg units are really fertile learning grounds from which to step off into something more specialized once you've learned the basics of nursing, such as head to toe assessment, pathophysiology and pharmacology, the "soft" skills of therapeutic communication, and of course, prioritization and time management.
There is absolutely no shame in admitting that you need more nursing experience before starting in the ED, and while I respect M/S nursing for its role as a specialty, there is no better learning ground for those who want a solid foundation before they make the leap into an area such a ED or ICU.